As shown in FIG. 1, a wooden drum 10 of the prior art is made of a plurality of layers of thin wooden sheets 11. The thin wooden sheets 11 are generally made of the discarded wood. There are often voids that are present between layers of the wooden sheets 11. It is technically difficult to avoid the formation of voids when the wooden drum 10 is made. The poor quality of the thin wooden sheets 11 and the voids can prevent the drum 10 from producing good quality sound.